I don't have a single problem with this build. Have you updated the firmware? I´m using 953_GEN_PACK-1.152683.0.158868.2 radio.
You also can try to flash Dark Ages Cuarto 3.18.124 kernel, I'm gonna make this change since I really don't like Zucc non-treble kernel.
Thank you so much! Switching to global solved the problem.I encountered something similar in the past too
The problem appeared when I selected only 4G band and the Volte didn't work properly. The phone tries to switch to 3g but it can't do it so it gives you "call ended". To solve the problem I selected the global mode or one which included 2g 3g 4g
So try to see if volte is selected and if the band is only 4g mode
/* * Your warranty is now void. * * I am not responsible for bricked devices, dead SD cards, * thermonuclear war, or you getting fired because the alarm app failed. Please * do some research if you have any concerns about features included in this ROM * before flashing it! YOU are choosing to make these modifications, and if * you point the finger at me for messing up your device, I will laugh at you. */